What is the temperature at which a solid melts?

Generally speaking, solid turns to a liquid at it's melting point. Ice turns to water at 0 degrees Celcius. Chocolate melts at 25 degrees Celcius-Yum! Ice (solid) thaws when the temperature rises above 32 degrees Fahrenheit, becoming water (liquid). Other solids (oddly) vary. your welcome

1 a is your answer I hope this helps

1) Answer is: c. gas.

The state of matter depends on the kinetic energy of the particles of matter.

The average kinetic energy of molecules depends on the temperature.

As temperature increases, molecules gain more energy from surrounding and move faster.

Kinetic energy (standard unit is the joule J) depends on speed of the molecule.

2) Answer is: d. plasma.

Plasma is a an ionised gas with highly electrical conductivity.

It is an electrically neutral with positive and negative particles.  

Plasma may be the most abundant form of matter in the universe.  

Plasma was first described by chemist Irving Langmuir.  

3) Answer is: d. gas and liquid.

In solid, molecules are closely packed, stiff and do not changes of shape or volume. Solid object (for example iron) does not take on the shape of its container.  

Liquids have definite volume, but no fixed shape.  

Gases (for example nitrogen and neon) not have definite volume and fixed shape, it depends on its container.  

4) Answer is: a. helium.

Helium (He) is noble gas.

Noble gases are in group 18: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) and radon (Rn). They have very low chemical reactivity.

Helium has atomic number 2, it has 2 protons and 2 electrons.

Electron configuration of helium atom: ₂He 1s².

Other substances in this example are solid and liquid state of matter.

5) Answer is: b. Its particles can move past and bump into each other.

Liquids flow and take the shape of their containers.

The attractive forces in liquids are weaker than those in solids.

For example, chemical compound water (H₂O) is liquid. Molecules of water are not rigid as in solid state (ice) and can move. Molecules move through out the container.

6) Answer is: c. It can take the shape of its container.

Gases do not have definite volume and fixed shape, it depends on its container.  

Liquids has larger densities than gases, because atoms or molecules in liquids are much more closer to each other than in the gases, that is because molecules in liquids have stronger intermolecular forces and therefore stronger interactions.

Its particles are not held in plase, the particles are far apart and move freely.

7) Answer is: d. Its shape is not fixed.

Plasma is a state of matter that resembles a gas, it lacks a fixed volume and shape.

Plasma can conduct electricity and has magnetic properties.

There are four fundamental states of matter (gas, liquid, solid and plasma).

Plasma can be artificially made by heating a neutral gas to a strong electromagnetic field.

a) false b) true c) true d) false and e) true

Explanation:

a) false.   All the energy applied is used for the phase change, so the temperature remains constant.

b)   true.   The kinetic energy is associated with the speed of the particles and they have more mobility in the liquid, therefore, more kinetic energy.

c)   true.   Since energy is used for state change

d)  false.   In general, mobility and temperature are proportional

e)  true.  Heat is the source of energy for the change of state

a. Temperatures increase can change a solid to a liquid, but cannot change a liquid to a solid

b. The particles in a solid are much closer together than the particles in a liquid.

Explanation:

Any material expands when heated and contracts when cooled. So, when a body is heated to a particular temperature, it starts melting and changes into a liquid.

As the material expands the distance between the atoms or molecules increases and it will become a liquid. So it can move around the material. It doesn't become solid on further heating. But water is an exception where it contracts when heated from 0° to 4° C.

In solids, these atoms or molecules are closely packed. It is rigidly fixed.

The solid, as well as the liquid, has a definite volume, but the liquid does not have a definite shape.

Answer : Option A) Fluorine is a gas and iodine is a solid at room temperature.

Explanation : With the given information it is known that the weaker force is less stable to hold its molecule together. This makes to assume that one substance may be solid and the other might be liquid or gaseous.

But, experimentally fluorine exists in gaseous state and iodine is a solid at room temperature.

The dispersion force in fluorine is weaker as it has less electrons as compared to that of iodine.

c. 5.crust (lithosphere) --plates that average about 30 km in thickness and 25°c in temperature.

4.upper mantle (asthenosphere) -- Solid rock about 720 km thick that flows from plasticity. Temperature is about 850 degrees Celsius.

3.lower mantle -- Solid rock about 2,200 km thick. Temperature is about 3,000 degrees.

2.outer core -- Very dense liquid of iron and sulphur about 2,250 km thick. Temperature is about 4,000 degrees Celsius.

1.inner core -- Made of solid iron about 1,200 km thick. temperature is about 7,000 degrees Celsius.

Explanation:

The earth's structure composition is highlighted in the above description form the top layers to the bottom layers of the earth and thus the lithosphere, asthenosphere and the outer and inner zones of the earth are formed on basis of the tectonic composition of the earth through the geologic past.

Explanation:

a)  the temperature at which the  first solid phase  form is calculated upon the cooling from 700°c , the first solid phase form at the temperature at which a vertical line at their composition intersect the line L - ( ∝ + L) Phase boundary i.e about 360°c.

b) What is the composition of this solid phase?  ; the composition of the first solid phase form corresponds to the intersection with the ∝ - (∝+L) phase boundary at a line constructed across the  (∝+L) phase.  Region at 560°c i.e 21wty. Pb or -79wty.mg

c) temperature at which the liquid completely solidify is about 465°C which is obtained by the intersection of the composition. wt; pbg so with the eutectic isotherm , i.e about 465°c.

d) the composition of the last remaining liquid face prior to the complete solidification corresponds to the eutectic composition. i.e 67wty.Pb - 33wty. mg

Explanation:

Phase change is said to occur when a substance from one state of matter changes to another state. Phase change occurs at a fixed  temperature. For example, water boils and converts to steam at 100°C. During the phase change, the average kinetic energy of the system  remains constant which is indicated by constant temperature. Actually, the molecular motion does increase with increase in heat but heat is absorbed in breaking the bonds and formation of new bonds.

Thus, third and last statement are correct.

Explanation:

Question 8:

c. The particles in a solid are much closer together than the particles in a liquid.

The particles of solids are much more close together when compared to the particles of liquids. Solids and liquids are typically both states of matter with striking differences. Below are some characteristics of solids:

Solid particles are closely and tightly held together by a very strong attractive force compared to any state of matter. Solids usually have definite shape and a fixed volume. Liquids also have fixed volume that does not readily change.

Matter usually undergo phase changes from one physical state to another.

Learn more:

Ionic solid

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Question 9:

a. can flow

Gases and liquids can flow and are both considered as fluid. A solid is a rigid substance that does not share this property of fluids.

A fluid is able to conform to the shape of the containers they occupy. Solids have their own fixed shape and volume and do not fill containers. Solids like liquids are typically in-compressible due to the nature of their packing. It takes a great deal of pressure of achieve little compression in liquids. When a solid is forcefully compressed, it deforms it. Both gases and liquids are called fluid due to their ability to flow readily.

Learn more:

Properties of matter

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Question 10

c. Move faster

When a solid is heated, the particles moves faster. Eventually, the solid will turn into a liquid as the temperature increases.  

The effect of heat on substances is that it increases the kinetic energy of the particles that makes them up. Solids are no exemption to this.  

The particles of solids have an orderly arrangement of their atoms.  When heat is applied, the particles starts vibrating about their fixed position.  More heat will eventually cause the vibrational energy to overcome the forces binding the atoms together.   When this happens, the particles becomes free to move about.   Here, vibrational energy transitions into kinetic energy.   Therefore, heat is directly proportional to the kinetic energy of particles of solids.  

 

Learn more:  

Kinetic energy

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Questions 11-19 can be answered together. Let us make an attempt to understand the terms, physical change, physical characteristics,  chemical change and chemical characteristics.  

A physical change is a change in which the physical properties of matter such as it's form and state are altered. Physical change is typified by  the following characteristics:

They are easily reversible i.e they can be returned back to their original form.   no production of new kinds of matter.   no mass change occurs in a physical change.   it requires little to no energy.  

 

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Physical change

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A physical characteristics of a substance describes the properties of matter that tells us what a substance when no change is happening to it.  Physical characteristics are perceived and observed with our senses or instruments or apparatus in a laboratory.  

 Examples of physical characteristics are color, taste, melting point, boiling point e.t.c  

   

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physical property

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A chemical change is a kind of change in which a new kind of matter is formed. Examples are Combustion, rusting of iron, precipitation, souring of milk.  

They typically have the following properties:  

they are not easily reversible.  leads to the production of new kinds of matter involves changes in mass.  requires considerable amount of energy.  

 

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chemical change

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Chemical characteristics of matter are properties that tells about what a substance can do as regards to whether or not it reacts  with other substances.  

Examples are flammability, rusting of iron, decomposition of water electric current e.t.c Chemical properties are results of the valence electrons in the outermost shell of an atom.  

 

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Chemical property

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Now to the

11. chemical and physical change

12. physical characteristics  

13. chemical change

14. chemical characteristics    

15. physical change

16. Chemical characteristics

17. physical change

18.  physical property.  

19. Physical change

Question 20

c. different samples have different properties

All different samples of a compound have the same properties. A sample is a fraction of a whole substance. If different samples are taken from a compound,  they will all have the same chemical properties.  

A compound forms when two or more elements combines together.  Properties of compounds are distinct and different from the individual elements that combined in its make up.  Compounds are usually represented by chemical formula.  

   

Learn more:  

Compounds

 

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